/* --- 全局变量 --- */
        :root {
            --primary: #1a1a1a;
            --secondary: #666;
            --bg: #fcfcfc;
            --border: #e2e8f0;
            --link-hover: #2b6cb0; /* 链接悬停色：科技蓝 */
        }

        body {
            margin: 0;
            font-family: "Helvetica Neue", Helvetica, "PingFang SC", "Microsoft YaHei", sans-serif;
            background-color: var(--bg);
            color: var(--primary);
            line-height: 1.6;
            /* 统一纹理背景 */
            background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noiseFilter'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noiseFilter)' opacity='0.04'/%3E%3C/svg%3E");
        }

        .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
        a { text-decoration: none; color: inherit; transition: 0.2s; }

        /* --- 头部搜索区 --- */
        .doc-header {
            text-align: center;
            padding: 80px 0 60px;
            background: linear-gradient(to bottom, #fff 0%, var(--bg) 100%);
            border-bottom: 1px solid rgba(0,0,0,0.03);
        }

        .doc-title { font-size: 36px; font-weight: 300; margin-bottom: 10px; }
        .doc-subtitle { color: #999; margin-bottom: 40px; font-size: 14px; }

        .search-wrapper {
            max-width: 600px;
            margin: 0 auto;
            position: relative;
        }
        
        .search-input {
            width: 100%;
            padding: 18px 25px;
            padding-right: 60px;
            border-radius: 50px;
            border: 1px solid #ddd;
            font-size: 16px;
            outline: none;
            box-shadow: 0 10px 30px rgba(0,0,0,0.03);
            transition: all 0.3s;
        }
        .search-input:focus {
            border-color: var(--primary);
            box-shadow: 0 10px 30px rgba(0,0,0,0.08);
        }
        
        .search-btn {
            position: absolute;
            right: 10px;
            top: 50%;
            transform: translateY(-50%);
            background: var(--primary);
            color: #fff;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            border: none;
            cursor: pointer;
            display: flex;
            justify-content: center;
            align-items: center;
        }

        /* --- 核心内容区：卡片网格 --- */
        .doc-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr); /* 一行三个 */
            gap: 30px;
            padding: 60px 0 100px;
        }

        .doc-card {
            background: #fff;
            border: 1px solid var(--border);
            border-radius: 12px;
            padding: 30px;
            transition: all 0.3s ease;
            display: flex;
            flex-direction: column;
            position: relative;
            overflow: hidden;
        }

        .doc-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 20px 40px rgba(0,0,0,0.06);
            border-color: #ccc;
        }

        /* 卡片顶部装饰条 (可选，增加设计感) */
        .doc-card::before {
            content: '';
            position: absolute;
            top: 0; left: 0; width: 100%; height: 4px;
            background: #f0f0f0;
            transition: 0.3s;
        }
        .doc-card:hover::before { background: var(--primary); }

        .card-header {
            display: flex;
            align-items: center;
            margin-bottom: 25px;
            padding-bottom: 20px;
            border-bottom: 1px solid #f5f5f5;
        }
        
        .card-icon {
            font-size: 24px;
            margin-right: 15px;
            background: #f9f9f9;
            width: 45px;
            height: 45px;
            display: flex;
            justify-content: center;
            align-items: center;
            border-radius: 8px;
        }
        
        .card-title { font-size: 18px; font-weight: 600; }

        /* 文章列表 */
        .article-list {
            list-style: none;
            padding: 0;
            margin: 0;
            flex-grow: 1; /* 撑开高度，保证底部对齐 */
        }

        .article-list li {
            margin-bottom: 12px;
        }

        .article-link {
            font-size: 14px;
            color: #555;
            display: flex;
            align-items: center;
            padding: 5px 0;
            white-space: nowrap;   /* 强制文本不换行 */
            overflow: hidden;      /* 隐藏溢出的内容 */
            text-overflow: ellipsis; /* 溢出部分显示为省略号 */
            max-width: 100%;       
        }
        
        .article-link::before {
            content: '📄';
            font-size: 10px;
            margin-right: 8px;
            opacity: 0.5;
            filter: grayscale(100%);
        }

        .article-link:hover {
            color: var(--link-hover);
            transform: translateX(5px); /* 悬停时轻微右移 */
        }

        /* 底部查看更多 */
        .card-footer {
            margin-top: 25px;
            padding-top: 15px;
            border-top: 1px dashed #eee;
            text-align: right;
        }
        
        .view-more {
            font-size: 12px;
            font-weight: 600;
            color: #999;
            display: inline-flex;
            align-items: center;
        }
        
        .view-more:hover { color: var(--primary); }
        .view-more::after {
            content: '→';
            margin-left: 5px;
            transition: 0.2s;
        }
        .view-more:hover::after { margin-left: 10px; }

        /* 响应式 */
        @media (max-width: 992px) {
            .doc-grid { grid-template-columns: repeat(2, 1fr); }
        }
        @media (max-width: 600px) {
            .doc-grid { grid-template-columns: 1fr; }
        }